Hello Scotty, (My up-front apologies for the long post)

My Mustang also has a (6R80) 6-speed automatic transmission, purely stock with only 14,200 miles on it. About 2 months ago, it threw the dreaded "Wrench" warning light and shows "See Manual". The manual doesn't specify anything either. Right after throwing the wrench light, I noticed that the Stang started hard-shifting from 1st to 2nd and then from 2nd to 3rd gears. Once I turned off the car and restarted it later, the light disappeared, but the shifting remained hard. I usually drive the Stang in "Track Mode", so I started driving in Normal Mode. This seemed to correct the problem until 2 weeks ago when driving normally, it hard shifted into 2nd gear again and then when shifting to 3rd gear, it went into "Limp, or Failsafe" mode and threw the Wrench Light again. Had to limp it home 2 miles away. I shut off the car and manually went into E.T. mode to see if any DTC's showed up and nothing. No history either.

I took the Stang to AutoNation Ford in Valencia CA the next day. I spoke to the mechanic at Ford who checked the car with their Ford IPS computer while test driving it. The mechanic stated that the only code that showed up was P0017 and stated that the transmission was bad and needed to be completely overhauled at a cost of $4300. He also stated that the AT Fluid looked brown and smelled burned. Not sure how he checked that as there is no dip stick available to check the fluid unless the pan is dropped which wasn't done. After doing some research, the P0017 code will throw a Check Engine light, which has never happened. This code is specifically identified as "Crankshaft Position - Camshaft Position Correlation (Bank 1 Sensor B)". This can happen for multiple reasons. However, I do not believe that is the problem as a problem like that would shut down the engine and not correct itself.

After further discussion with the mechanic, I advised him to keep to keep the car over-night and test drive it again the next day in "Track Mode" to see if it would throw the Wrench Light again. He did so and it did shift hard as stated above but didn't show the wrench light. However it did throw a different code of P0717 defined as "“Input/Turbine Speed Sensor “A” Circuit No Signal.” The mechanic then changed his tune and stated they need to replace the speed sensor. Since the sensor is internal in the transmission, they need to drop the pan, take off the solenoid valve  body to access the speed sensors (input and Output) which are integrated into a frame rail. Estimated repair cost would then be only $1675.

After doing more research again, I found the following:

Common mistakes when diagnosing the P0717 code

Some of the symptoms involved with a P0717 code can be misleading and can result in a few different misdiagnoses. The most common of these include:

• Assuming there’s an internal transmission problem.
• Trying to resolve the engine misfiring problem without understanding what’s causing it.
• Replacing the speed sensor unnecessarily.
• Assuming the problem is a vehicle speed issue.

What repairs can fix the P0717 code?

The right repair for the job will depend entirely on the underlying cause of the problem. Some of the most likely repairs to fix a P0717 code are:

• Replacing the valve body.
• Replacing the input/turbine speed sensor. (attached to leaf frame?)
• Replacing one or more shift solenoids.
• Replacing or repairing damaged, shorted, or open wiring or circuits.
• Replacing the engine coolant temperature sensor
• Draining, flushing, and replacing the transmission fluid

Additional comments for consideration regarding the P0717 code

It should be obvious from the symptoms associated with this code that it should be dealt with immediately. In addition to making it more difficult and dangerous to drive your car, this code will illuminate the Check Engine light and make it impossible to pass an OBD-II emissions test to renew your vehicle’s registration.

DTC P0717 sets when P0715 is set.

I had Ford finish up the Oil Change and stated I'm getting a second opinion. Since my warranty expired last March of 2022 I took it to a highly rated auto mechanic repair shop. After doing all the necessary checks on all wiring, their OBDII showed a problem with the Transmission Speed Sensor as well. (Not sure what code they found). They stated the same process for repair as Ford to replace the sensors (input and Output) for under $1500. 

Finally my question:

I've also read that there could be a malfunction within the PCM not reading the TSS's correctly. What would you recommend in this complicated case? Replace the PCM and change the AT Fluid to see if problem solved or go the route that the mechanics are suggesting by replacing the TSS's? The TSS's cost less for parts but is labor intensive where as the PCM is only a few hundred bucks and easily replaced. 

As a side note, I understand that the TSS problems in the Ford automatic transmissions (most Models of vehicles) have had problems since 2005. You would think they would have corrected this since then.

I respect any advise you may have, Thanks,

Mike H